using System;
using UnityEngine;
using System.Linq;
using System.IO;
using System.Text.RegularExpressions;
using System.Collections.Generic;
using Object = UnityEngine.Object;

namespace UnityEditor
{
	internal class NewScriptGenerator
	{
		private const int kCommentWrapLength = 35;
		
		private TextWriter m_Writer;
		private string m_Text;
		private ScriptPrescription m_ScriptPrescription;
		private string m_Indentation;
		private int m_IndentLevel = 0;
		
		private int IndentLevel
		{
			get
			{
				return m_IndentLevel;
			}
			set
			{
				m_IndentLevel = value;
				m_Indentation = String.Empty;
				for (int i=0; i<m_IndentLevel; i++)
					m_Indentation += "	";
			}
		}
		
		private string ClassName
		{
			get
			{
				if (m_ScriptPrescription.m_ClassName != string.Empty)
					return m_ScriptPrescription.m_ClassName;
				return "Example";
			}
		}
		
		public NewScriptGenerator (ScriptPrescription scriptPrescription)
		{
			m_ScriptPrescription = scriptPrescription;
		}
		
		public override string ToString ()
		{
			m_Text = m_ScriptPrescription.m_Template;
			m_Writer = new StringWriter ();
			m_Writer.NewLine = "\n";
			
			// Make sure all line endings are Unix (Mac OS X) format
			m_Text = Regex.Replace (m_Text, @"\r\n?", delegate(Match m) { return "\n"; });
			
			// Class Name
			m_Text = m_Text.Replace ("$ClassName", ClassName);
			m_Text = m_Text.Replace ("$NicifiedClassName", ObjectNames.NicifyVariableName (ClassName));
			
			// Other replacements
			foreach (KeyValuePair<string, string> kvp in m_ScriptPrescription.m_StringReplacements)
				m_Text = m_Text.Replace (kvp.Key, kvp.Value);
			
			// Functions
			// Find $Functions keyword including leading tabs
			Match match = Regex.Match (m_Text, @"(\t*)\$Functions");
			if (match.Success)
			{
				// Set indent level to number of tabs before $Functions keyword
				IndentLevel = match.Groups[1].Value.Length;
				bool hasFunctions = false;
				if (m_ScriptPrescription.m_Functions != null)
				{
					foreach (var function in m_ScriptPrescription.m_Functions.Where (f => f.include))
					{
						WriteFunction (function);
						WriteBlankLine ();
						hasFunctions = true;
					}
					
					// Replace $Functions keyword plus newline with generated functions text
					if (hasFunctions)
						m_Text = m_Text.Replace (match.Value + "\n", m_Writer.ToString ());
				}
				
				if (!hasFunctions)
				{
					if (m_ScriptPrescription.m_Lang == Language.Boo && !m_Text.Contains ("def"))
						// Replace $Functions keyword with "pass" if no functions in Boo
						m_Text = m_Text.Replace (match.Value, m_Indentation + "pass");
					else
						// Otherwise just remove $Functions keyword plus newline
						m_Text = m_Text.Replace (match.Value + "\n", string.Empty);
				}
			}
			
			// Put curly vraces on new line if specified in editor prefs
			if (EditorPrefs.GetBool ("CurlyBracesOnNewLine"))
				PutCurveBracesOnNewLine ();
			
			// Return the text of the script
			return m_Text;
		}
		
		private void PutCurveBracesOnNewLine ()
		{
			m_Text = Regex.Replace (m_Text, @"(\t*)(.*) {\n((\t*)\n(\t*))?", delegate(Match match)
			{
				return match.Groups[1].Value + match.Groups[2].Value + "\n" + match.Groups[1].Value + "{\n" +
					(match.Groups[4].Value == match.Groups[5].Value ? match.Groups[4].Value : match.Groups[3].Value);
			});
		}
		
		private void WriteBlankLine ()
		{
			m_Writer.WriteLine (m_Indentation);
		}
		
		private void WriteComment (string comment)
		{
			int index = 0;
			while (true)
			{
				if (comment.Length <= index + kCommentWrapLength)
				{
					m_Writer.WriteLine (m_Indentation + "// " + comment.Substring (index));
					break;
				}
				else
				{
					int wrapIndex = comment.IndexOf (' ', index + kCommentWrapLength);
					if (wrapIndex < 0)
					{
						m_Writer.WriteLine (m_Indentation + "// " + comment.Substring (index));
						break;
					}	
					else
					{
						m_Writer.WriteLine (m_Indentation + "// " + comment.Substring (index, wrapIndex-index));
						index = wrapIndex + 1;
					}
				}
			}
		}
		
		private string TranslateTypeToJavascript (string typeInCSharp)
		{
			return typeInCSharp.Replace ("bool", "boolean").Replace ("string", "String").Replace ("Object", "UnityEngine.Object");
		}
		
		private string TranslateTypeToBoo (string typeInCSharp)
		{
			return typeInCSharp.Replace ("float", "single");
		}
		
		private void WriteFunction (FunctionData function)
		{
			string paramString = string.Empty;
			string overrideString;
			string returnTypeString;
			string functionContentString;
			
			switch (m_ScriptPrescription.m_Lang)
			{
			case Language.JavaScript:
				// Comment
				WriteComment (function.comment);
				
				// Function header
				for (int i=0; i<function.parameters.Length; i++)
				{
					paramString += function.parameters[i].name + " : " + TranslateTypeToJavascript (function.parameters[i].type);
					if (i < function.parameters.Length-1)
						paramString += ", ";
				}
				overrideString = (function.isVirtual ? "override " : string.Empty);
				returnTypeString = (function.returnType == null ? " " : " : " + TranslateTypeToJavascript (function.returnType) + " ");
				m_Writer.WriteLine (m_Indentation + overrideString + "function " + function.name + " (" + paramString + ")" + returnTypeString + "{");
				
				// Function content
				IndentLevel++;
				functionContentString = (function.returnType == null ? string.Empty : function.returnDefault + ";");
				m_Writer.WriteLine (m_Indentation + functionContentString);
				IndentLevel--;
				m_Writer.WriteLine (m_Indentation + "}");
				
				break;
				
			case Language.CSharp:
				// Comment
				WriteComment (function.comment);
				
				// Function header
				for (int i=0; i<function.parameters.Length; i++)
				{
					paramString += function.parameters[i].type + " " + function.parameters[i].name;
					if (i < function.parameters.Length-1)
						paramString += ", ";
				}
				overrideString = (function.isVirtual ? "public override " : string.Empty);
				returnTypeString = (function.returnType == null ? "void " : function.returnType + " ");
				m_Writer.WriteLine (m_Indentation + overrideString + returnTypeString + function.name + " (" + paramString + ") {");
				
				// Function content
				IndentLevel++;
				functionContentString = (function.returnType == null ? string.Empty : function.returnDefault + ";");
				m_Writer.WriteLine (m_Indentation + functionContentString);
				IndentLevel--;
				m_Writer.WriteLine (m_Indentation + "}");
				
				break;
				
			case Language.Boo:
				// Comment
				WriteComment (function.comment);
				
				// Function header
				for (int i=0; i<function.parameters.Length; i++)
				{
					paramString += function.parameters[i].name + " as " + TranslateTypeToBoo (function.parameters[i].type);
					if (i < function.parameters.Length-1)
						paramString += ", ";
				}
				overrideString = (function.isVirtual ? "public override " : string.Empty);
				returnTypeString = (function.returnType == null ? string.Empty : " as " + TranslateTypeToJavascript (function.returnType));
				m_Writer.WriteLine (m_Indentation + overrideString + "def " + function.name + " (" + paramString + ")" + returnTypeString + ":");
				
				// Function content
				IndentLevel++;
				functionContentString = (function.returnType == null ? "pass" : function.returnDefault);
				m_Writer.WriteLine (m_Indentation + functionContentString);
				IndentLevel--;
				
				break;
			}
		}
	}
}

